Self-concept is seen as constantly changing, being revised and updated rather than static and stagnant. Individuals are not born with self-concepts intact--an individual may accommodate characteristics that might influence the development of the self-concept, but the actual development is a learned process. This study investigated the self-concepts of 35 individuals diagnosed as chronic mentally ill. The independent variables investigated were duration of partial hospitalization, gender, diagnosis, and chronological age. The dependent variables employed were scores from 10 subscales of the Tennessee Self Concept Scale. The subscales were: physical self, moral-ethical self, personal self, family self, social self, self-criticism, identity, self-satisfaction, behavior, and total P scores (items measuring an individual's overall perception of self). Data were analyzed by testing four composite null hypotheses employing three way analysis of variance. The results appeared to support the following generalizations: (1) chronic mentally ill males possess a higher self-concept than females for family self, identity, and total P scores; (2) the longer the duration of partial hospitalization of the chronic mentally ill individuals, the lower the self-concept for physical self, personal self, family self, and behaviors; and (3) chronic mentally ill individuals 33 years and older have a higher self-concept than those individuals 32 years and younger. (Author/LLL)